1. Field of the Invention
This invention relates to a connector and more particularly to a connector having a double locking construction.
2. Statement of the Prior Art
For convenience of explanation, a prior connector having a double locking construction will be described below by referring now to FIGS. 9 to 12. FIG. 9 is a cross sectional view of the prior connector, illustrating a retainer 52 in a temporary mounting position. FIG. 10 is a cross sectional view of the prior connector illustrating the retainer 52 in a permanent mounting position. FIG. 11 is a cross sectional view of another prior connector, illustrating a retainer 62 in a temporary mounting position. FIG. 12 is a cross sectional view of another prior connector illustrating the retainer 62 in a permanent mounting position.
In the prior connector shown in FIG. 9, a terminal element 58 is inserted into a terminal-accommodating hole 55 in housing 51 from the rear side end of the hole. Then, a cap like retainer 52 is mounted on the rear side end of the terminal-accommodating hole 55 and the retainer 52 is moved from a temporary mounting position shown in FIG. 9 to a permanent mounting position shown in FIG. 10.
In order to allow the terminal element 58 to be inserted into the terminal-accommodating hole 55, the retainer 52 must permit the terminal element 58 to enter therein. Thus, in the prior connector, an engaging means (not shown) temporarily supports the retainer above an axis X of the terminal-accommodating hole 55. After the terminal element 58 is inserted into the hole 55, the retainer 52 is pushed down in a direction shown by an arrow A and advanced in a direction shown by an arrow B.
On the other hand, in another prior connector shown in FIG. 11, a terminal element 63 is inserted into a terminal-accommodating hole 65 in a housing 61 from the rear side end of the hole. Then, a plug like retainer 62 is pushed into the terminal-accommodating hole 65 from the rear side end and the retainer 62 is moved from a temporary mounting position shown in FIG. 11 to a permanent mounting position shown in FIG. 12.
The retainer 62 is provided with a flexible and long terminal lock piece 66 which pushes the terminal element 63. On the other hand, the terminal-accommodating hole 65 has an accommodating space 65a for accommodating the terminal lock piece 66 on an upper rear portion and the space 65a is communicated with a front side end of the terminal-accommodating hole 65 along a slant wall 65b. Thus, in order to move the retainer 62 to the permanent mounting position the retainer is pushed forwardly in a direction shown by an arrow B and the terminal lock piece 66 is deflected along the slant wall 65b so that the lock piece 66 engages with a recess 63a.
The former connector requires two operating steps of pushing down the retainer 52 in the direction A and advancing it in the direction B so as to displace it to the permanent mounting position. Consequently, the former connector requires a skilled worker. This impedes automatic insertion of a terminal.
The latter connector requires a great force for pushing the retainer 62 to the permanent mounting position in the case that the number of the terminal elements to be inserted is many, since the terminal lock piece 66 is deflected upon inserting the retainer 62 into the permanent position. Also, in the case of inspecting the connector in the future, it will be impossible to draw the terminal element 63 out of the connector since the terminal lock piece 66 loses its recovery force and deflects downwardly as it is, even if the retainer 62 is returned to the temporary mounting position.